I’m similar to you, I’m at level 40 now but I started 5 years ago and I’ve been in Japan for most of that time. I spent nearly a year on level 15 during my first year on JET becaues I was focusing on immersion and survival in Japan. I picked WaniKani back up when the pandemic started and have been chugging along since.
I passed N3 in 2019 and N2 in 2021, and I took N1 last month. I’m always a little surprised seeing people on levels even higher than me considering if they should sign up for N4 or N3, but I suppose they’ve dedicated more time to kanji and less to other things like grammar and listening. That’s a personal choice, but it’s going to be difficult to integrate your skills later if you don’t improve them all along the way. If you actually want to use Japanese in a way other than grinding WaniKani, then reading texts, speaking, listening, and writing are necessary and will reinforce your kanji knowledge along the way, so you don’t forget after “burning”. Since I live in Japan I see kanji every day, I read the news in Japanese, etc. In my textbooks, on the news, and in life I learn new kanji that haven’t come up with WaniKani yet, and that makes them easier to learn when they eventually come up. All the study methods reinforce each other.
I wish I had time to grind more on WaniKani and get my averages below 30 days per level, but I’m far more interested in actually learning using Japanese and surviving here than getting to level 60. Also, I have a full-time job. But I do want to get there by the end of the year. If not? Next year, then